This invention relates to strollers for infants. More specifically, this invention relates to a lightweight, collapsible infant's stroller which is quickly and easily movable between an unfolded operating position and a low-profile folded position.
Collapsible infant's strollers are well known in the prior art, and have become increasingly popular in recent years with the advent of so-called umbrella strollers. Strollers of this type typically comprise a lightweight tubular folding framework having wheels and a lightweight fabric seat. These strollers are designed for quick and easy movement between an operating position and a relatively compact folded position for easy transporting. Such strollers have been found to be advantageous over older, more conventional types of infant's strollers which are heavier and bulkier in design.
Umbrella-type collapsible strollers of the prior art have not been totally satisfactory in that they have not provided a lightweight mechanical framework of sufficient rigidity for prolonged use over a period of years. For example, many of such strollers require a framework having two-part side frames which fold upon themselves to assume a collapsed position. See U.S. Pat. Nos. 3,390,893 and 3,871,738. In an operating position, the side frames are laterally spaced by a toggle link. However, over a period of time, the toggle link tends to work loose and thereby allows the side frames to become loose with the stroller in an operating position. In some instances, the toggle link has been known to disengage suddenly during use whereby the stroller without warning tends to move to a collapsed position. This is highly undesirable when a small infant is in the stroller.
Some prior art strollers have used various sliding joint connections in an effort to obtain greater frame rigidity by eliminating fold-over tubing constructions. See, for example, U.S. Pat. No. 3,024,035. Such strollers use the sliding joint connections to allow portions of the framework to slide with respect to a pair of elongated rigid side frames. However, such prior art strollers have resulted in a folded construction with the front and rear wheels folded on top of each other on opposite sides of the side frames. This folded construction is not ideally compact, and requires additional locking means for maintaining the stroller in a folded position. Moreover, prior art strollers having sliding joint connections have not eliminated toggle links for laterally spacing the side frames in an operating position, and accordingly have not eliminated the tendency of these toggle links to work loose during operation.
This invention provides an improved lightweight collapsible infant's stroller which is quickly and easily moved between operating and folded positions, and which has locking means for positively maintaining the stroller in an operating position. Further, this invention provides a collapsible stroller which, when folded, assumes a low-profile compact configuration, and does not require separate locking means for maintaining the stroller in a folded position.